Rotary valve for internal-combustion engines.



E. M. BOUBNO NVI LLE. RUTAHY VALVE FOR INTERNAL CI JMBUSTION ENGINES.

APPLICATlON FILED L14. 1911- Patented Dec.18.1917.

2 SNEETSSHEET l.

4. w p a!- 00 w 471 a pa 9 m 7 1 2 w ll w ATT RNEY E. M. BOURNONVILLE. ROTARY VALVE FOR INTERNAL'COMBUSTION ENGINES.

APPLICATION HLED FEB. H, I911- Patented Dec.18.1917

2 SHEETSSHEET 2.

UNITED STATES PATENT OFFICE.

EUGENE M. BOUBNONVILLE, F JERSEY C ITY, NEW JERSEY BOTARY VALVE FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented Dec. 18', 1917.

Application flied February 14, 1917 Serial No. 148,508.

yented .certain new and useful Improve- 'n1ents inRotary Valves for-lnternal-Conr bustion Engines, of which the following is a s ecification. he invention relates to internal COll'lbllS-- tion engine valves of the type comprising a rotor turning in the bore of a casing, and embraces certain novel features in respect to the rotor and its casing having for their gen eral object to improve the lubrication and to reduce the possibility of sticking and scoring of the valve.

In the accompanying drawings illustrat- 1 ing the improvements:

Figure 1 is a vertical longitudinal section r-theupper art' of a multicylinder cngmef'e nbodying t e improvements;

Fig. 2'is' a projection of th rotary valve member;

Fig. '3. is a longitudinal section through a portion of the rotary valve member;

Fig. {is a, transverse section on the line e surface of the i In the 'valvevseleoted for illustration, a.- cyli-ndrical rotor 2 finds its bearing in the .bore of a ,water-cooledmasing' 3 extending over the 'topsof the cylinders 4 of. a multicylinder internal combustion engine, with which the bore communicates by ports 5, Intake an exhaust o enings 6 and 7 are 6 ,formed at opposite .si es, with the cylinder ports between them, the intakeopeningcommunicatir with a-manifold -8formed: in the bod of the casing and the exhaust open-ing wit o suitablejexternal manifold not -shown.

The intake opening preferablv eirteiids jsubstantially continuously for the lengthpfcthe bore; or ntolgeports forthe respective inders me'y be connected bye passage inst face of t s. hereto securega li ke efiect. The form o f'rotorillustrated has'laterel pockets. 9 constituting transfer ports, which connect the intake and exhaust ports alternately with the cylinder ports; and there may be two or three of these pockets for each cylinder so that the valve turns at one-quarter or onesixth. the speed of the crank-shaft.

burctcr traverses a longitudinal passage 10 in the interior of the rotary valve body before entering the intake manifold, from which the charges are admitted to the cylinclers' by the pockets 9 at the proper times. The valve is referably lubricated and sealed by lubricating oil introduced into the fuel, or into the fuel and air mixture, and carried. thereby to the surface of the rotor upon which it is deposited, A valve thus co11- stituted is of the kind disclosed in my Patents, No. 1,118,730 of November 24, 1.914, and No. 1,119,494 of December 1, 1914, and my application, Serial No. 65,655, filed December 8, 1915, to which the present improvements are particularly applicable though not necessarily confined. In the specific construction selected for illustration herein the fresh gases which flow through ,the valve passage 10 enter it at one end,

marked 11,,and passout at the opposite end through the connection shown at 12 into the adjacent end of the manifold 8, but the Part or all of the fresh fuel mixture from the cargases 35 may also be admitted to" the interior 0 the valve at the middle andflow out at both ends as disclosed in one form of my said applications As in. my prior cases the rotary valve member is made in two or more sections,

flexibly jointed between cylinders; as sented'at 13. A joint sleeveliuloosel in enlargements of the pass'agel-O att e 'ad joining ends of the sections bridges-the ul to prevent undue-freedom of passage-t "cre through;

Heretofore the eat difiiculty "with rote valve intern combustion engines, name y the tendency of the rotary member exposed to the-heat of the exhaust to bind in its casing, has caused those engaged upon the problem to seek to make the respective bearing surfaces as smooth and as absolutely cylindrical as possible. Contrary to exectation, I have made the discover? that Eeneficiitl' results in the avoidance 0 stick; ing'are obtained by providing a'rotor with a multiplicity of low regions,- superficial as and-of relatively lai'rgc ar'a, "distributed in any desired or irregular man ner over the exterior of the member, so that there is an overlapping of the areas thro The interior out the length of the valve. surface of the casin is preferably made smooth. I The effect 0 these low areas is to carry around film patches of luln'ican't, which continually restore the oil film between the rotor and easing wh'ch keeps the metal surfaces from touch1ng. Suchsuperficial low regions it 'w-ilLbe understood are to be distinguished from ooves cut into the valve, from which they dilfer both in structure and effect. While their precise depth ma naturally vary, a range of a quarter 0 a thousandth to three or four one-thousandths of an inch is believed to be fairly illustrative. tion are indicated in Fig. 2, where they are designated b the reference character 15.

As a furt 'er means of promoting lubrication and sealing, the rear side of the longitudinal opening 6 in the mnerwall of the casing which communicates with the intake manifold, is beveled at its inner edge, as indicated at 16 in Fig. 5, so as to cause the oil de osited from the fuel mixture upon the ace of the valve member to be urged as the result of the rotation of the latter into a wedge-like entrance, whence it square qdg,

is carried onward between the surfaces. The

behavior; of such an internally-beveled edge is directly opposed to that of a sharp or which acts as a wiper. By the rear side of the intake port or opening I mean,;o course, the side which is the later to be encountered'by a iven point on the valve member in the revolution of the latter.

I have also observed that at the end of a run a. certain amount of lubricating oil is left within thecentral valve passage 10, which when the engine is started a ain is drawn into the cylinders in suflicien quantity to cause an objectionable amount of smoke in the exhaust. To overcome this difficulty and at the same time increase the efficiency of the lubrication I now propose to provide the said interior passage between the pocket bearing portions of the valve with one or more encircling grooves 1-7, 17 constituting recesses wherein such dcposits are trapped by the action of centrifugal force as they move alongthe sprface of the bore under the suction of the engine. Small channels 18 leading frefin the bottoms of the grooves 17 outward thkiugh the wall of the valve to the member enable such trapped oil, still under theinfiuence of centrifugal force, to reach the bea ring surfaces of the rotor and easing, where it contributes to themaintenance of the desired oil film. Short longitudinal oil grooves 19 may be formed in the outside of the rotary member into which the channels 18 open at their outer ends, the said grooves preferably extending to within a'shortdistance of the ends of the valve pockets.

The low areas in ques- IWhere' oints occur between the ported o1 tions the valve member, the encirc ing grooves in the central passage may be ormed 1n the sleeve or sleeves 14,18 is illustrated in the case ,6! the cove 17'. 70 It is then suflicient to c -c annels 18 only through the sleeve, rice the break at the joint between the valve sections allords adequate passageway for the oil; and external grooves 19' leadi .frountheends of the valve sections per cm the same function as the grooves 19. The other great causeof sticking and cutting in' these valves, in addition to'failure of the oil film, is unequal expansion of the rotor and basing as they become heated during the running of the engine. 'For this reason it is necessary to provide a certain amount of initial clearance between the rotary member and the bore in which it 86 turns which diminishes as the engine heats up. This clearance requires to be carefully calculated, since'if too little is provided the valve member will expand until it is gripped in the casing, while anything above what is 00 necessary to prevent the valve ,becoming tight in its bore when fully heated tends to diminishthe power of the motor; on the other hand, because of the possibility of the engine becoming overheated at times from various causes, it is necessary to allow a .cer tain additional clearance above the theoretical requisite amount. .In the case of jlow speed engines I have found that by per-"'1'... construction of the valve, by eliicient cod and lubrication, and by makin the rotary member the proper amount sma ler tha the casing bore, for clearance as just descr i hiidg it is possible to produce a rotary valvc t' i which does not stick or score. With high speed en ines, however, the same and even greater egree of care in these respects is not sufficient to insure against cutt ng, the recurrence of which in these m'otors has proved a roblem articularly v:diilicult or 1.119 solution. fter stu y and experiment l have ascertained that the condition is caused by a; diflerential GXEILIXSIOIL in the lirotary valve member itself, t e eflect beingla raising of the lips of the ports, which receive the hot exhaust gases, suflicieiitly to produce a scraping or at least an excessive hearing at these regions, with resulting local destruction of the oil film atv the places Where it is most diilicult to main- Q pronounced at one or other of these edges, l0

above the general surface, I

. tion of thmaql imp o the particular conditions of 0 'tion. ihe lowering may be effected all way around the tunsverse edges as we as at the front and rear sides. Cutting'awayof the surface of thevalve member at the narrow or transverse edges of the ports, however, 15 n'nnor importance, and in fact it is suflicient to lower the surface only adjacent onset the longitudinal edges, that is to say the 11p, which, depending upon the direction of rota ye, is in the rear or following position. ThlSllP'flhlhQjlIIle of exhaust is artieularly exposed to""""theoutflgwing sated if left ull and sharp rises above the gen eral surface so as to const tute a scraping edge which removes the lubricant from they face of the bore of the casing. By slightly cutting down or beveling the rearllp, the

oil, instead of being scrapecholf, ma be wed d in between the surfaces as the rotor revo ves. A lowering extending all the Way around the port is indicated at in Fig. 55. The actual amount of cutting'away must depend upon the particular construction of the engine and valve, the diameter of the rotor, the amount. of piston displacement, and 111 general upon the conditions determinmgtbe quantity of heat distributed through the valve in a given time As a matter of measurement, the thickness of metal removed may range from, say, a half-thousandth of an inch for a two and one-half inch diameter valve to one-sixty-fourth of an inch for very large engines havin valves up to twelve inc es in diameter. 11 any particular case the extent of cutting-away must be do termined by suitable calculation. and trials.

is to say, the regions extendin It will be understood that the illustration of the regions 20 in the sectional views is exagrate The width of the lowered border at the edges of the valve ports will necessarily vary in different cases. For example, for a valve in the neighborhood of two and a half inches in diameter the region may be from one'quarter to one-half inch wideiit the longsides and onc eighth to one'quarter inch wide at the ends, the borders being low est at theininner edges, immediately adjacentthe valve pockets, and merging into the general surface toward their outer ortions. If desired the remainder of t ose parts of the surface of the valve member which are included in the port zones, that circumferentially from the lowered bor vers 15, ma

also be cut down, butto a less extent, pre. erably about a quarter of the depression of said borders. It is to be understood, however, that the intent is not to eliminate bearingntitheport zones'fbut rather to remove the materialwhich would be in excess at h l hfl l, 1 "Muted,

lriort at the ends or sees and subject to expansion, Enu----- member.

making of the insidcsof the ports or pockets of the valve inen'iber of separate pieces from,

the body, so as to diminish the amount'fof heat transmitted from the exhaust gases to the valve members This may be effected by providing the pockets with sheet metal linings S21, suitably secured in place. as mdicated bloc in Fig. @orby the use of insert ,such as shown in. Figs. 7 andy8, in which the pockets are formed and which are secured in any suitable way in recesses in the valve body. Th metal of such inserts may be of the same or (Illll lllel'lt character from that of the body of the rotary The top area of these inserts should be substantially the same as the area.

of the-ports or pocketsgat the surface of the valve body, the metal of the inserts so rounding the pockets being preferably tap ered to thin ed 22 at the top, which edges desirably terminate slightly below or inside the surface of the valve body. If desired asbestos or heatinsulating material-could be interposed between the linings 21 or the inserts 21 and the faces of the recesses in the valve body. 1,

What I claim as new is:

1. An internal coi'nbustion valve cox'uprising a casing having a bore with intake and exhaust openings at opposite sides, which are connected alternately with the cylinder by transfer ports m a rotor turning in the bore, the rear edge of the intake opening into the bore being beveled so as to form with the surface of the rotor a wedge-like entrance for lubricant.

2. A rotary valve for internal combustion engines comprising a rotary valve body turning in. the bore of a casing und huving an external pocket for connecting mtahc and mg in the bore of a casing and having an external pocket for, connecting intake and ex haust, 0 coin r at 0 posits sides alternately 'ith cylin er, and an internal longitudinal passage through which the tresh'gases are caused to pass, the said valve body being provided with'lubricant-catchin'g recesses in the surface of its interior passage, means for conducting the oil from grooves communicating with said means; 4

74:. A rotary valve for internalcombustion engines comprising a rotary driven valve body turning in the bore of a casing and pro-' vided with a, port controlling the exhaust, the exterior o fthe valve body where it borders on said port being lowered to allow for unequal expansion.

5. A rotary valve for internal combustion engines comprising a rotary driven valve body turning in the bore of a casing and provided with a port controlling the exhaust, the surface of the valve body inthe port zone and more especially immediately adjacent the port belng lowered to allow for unequal expansion.

6. 4A rotary valve for multicylinder in-- ternal combustion engines comprising acesing formed with a bore and having ports to the cylinders and intake and exhaust ports at opposite sides, and a rota valve body having external pockets constitutmg, trans fer ports for connecting said intake and exhaust ports alternately with the cylinder ports, the said yalve ized by the portions ing on the ports being the general surfaceto body bein characterof its sur ace bordersufiiciently lower than prevent an elevation at the port lips when the body is exposed'to the heat of th exhaust gases. a

7. In a rotary valve for internal -combustion engines, comprising a casing hav-' an exing a valve seat bore provided with haust ort and .a

ort communicating with the cy inder, a va ve body turning in said bore and having an external pocket constituting' a transfer port for. connecting the exhaust and cylinder ports, the surface of the valve body bordering uPonthe'reer lip of the transfer port being sllg'htlyxcut, down or beveled as and for the purpose set .forth.

EUGENE M. geoumaoNvI Ln.v 

